IMU
Compact & High-accuracy

Inertial Measurement Unit

FOG & MEMS combined IMU

TAG300AU7684MEMS IMU
i-FOG

01

02

Inertial Measurement Unit (IMU) is an electronic

device that measures various kinds of motions in

vehicle dynamics, attitude (roll & pitch) or heading(yaw) angle.

In addition, it is an essential technology inautonomous driving for localization anddead-reckoning. Tamagawa Seiki Co., Ltd. oﬀers wide
range of product, such as MEMS Gyro, FOG or AHRS.
We provide the best option for your application.

Automobile

IMU measures vehicle dynamics, attitude (roll & pitch) or
heading (yaw) angle. In addition, it is used forautonomous driving by combining GNSS.

Unmanned Construction Machine
IMU oﬀers stable output under large vibration by
utilizing gyroscope and accelerometer.

02

02

AttitudeControl for
Excavator

MotionSensing for
Amusement
Equipment

Under Ground
Navigator

Navigation forLarge Dump
Truck

03

04

Stabilization
for Ceiling
Crane
Navigation for
AGV

Unmanned Agricultural Machine
IMU detects attitude (roll & pitch) and heading (yaw)angle of agricultural tractor. In addition, it is used forautonomous driving by combining GNSS.

03

AttitudeControl for
Unmanned
Agricultural
Tractor

Security Robot

IMU is used for attitude control in security robot.

03

AttitudeControl for
Pesticide
Spraying
Helicopter

06

Navigation for
Unmanned
Forklift

05

Attitudecontrol ofmicrosatellite

04

Tilt
measurementof security
robotsAttitudeControl in
Rehabilitation

01

05

AttitudeControl for
Drone

Navigation for
AGV in Harbor

Bridge DeckDeﬂection

IMU is used for attitude control in drone.

Automated Guided Vehicle (AGV)

Gyroscope is used for AGV Magnetic Guidance to securehigh running stability.

Inertial
Navigation
System (INS)for Light
Aircraft

VehicleDynamics
Testing

07

07

MotionSensing for
Train

06

Drone

Train

IMU detects angular velocity and acceleration to measure
the comfort level of a train with GPS location information.

08

Navigation
System for Ship
Motion Sensing
on Deck
Stabilization for
Monitoring
Camera08

Ship

IMU is used for inertial navigation and motion detection ofships.

FOG ＆ MEMS combined IMU

FOG & MEMS combined IMU
Accuracy for full autonomous driving
FOG & MEMS combined IMU incorporates 3-axis gyro (i-FOG for Z
axis, MEMS gyro for X and Y axis) and accelerometers, whichmeasure angular velocity and acceleration. In addition, attitude(roll & pitch) and heading (yaw) is calculated. An external GNSS

module is connected to IMU; with position and speed data, IMU
can be used as GNSS / INS / VS navigation.

New Synergy created in combination with MEMS & FOG

Fiber Optic Gyroi-FOG
Heading

03

0.1 °/hMEMS IMU
Attitude

0.1 °FOG & MEMS combined IMU

New IMU : Bridging the Gap between cost and accuracy

The accuracy of Gyroscope is classiﬁed by principle of operation. The customer needs to choose the suitable gyroscope
depending on application or environment. FOG & MEMS combined IMU is a newly developed IMU with the concept of ﬁlling in
the gap of cost and accuracy.

H

MRLG

▶ Unmanned Airplane▶ Military Application

FOG IMU▶ Navigation System

Price▶ Mapping system for Underground vehicle

FOG & MEMS combined IMU
Attitude：0.1°

MEMS IMU▶ Vehicle Dynamics Testing▶ Self-driving support

Heading：0.1°/h▶ New technology for fully autonomous driving▶ Stable dead reckoning for a long period of time
▶ High accuracy and reasonable price▶ Dead reckoning with sensor fusionL

AccuracyL

H

Accuracy of Self-localization
Through the use of GNSS with centimeter-level positioning accuracy, fully autonomous driving will come closer to realization.
However, the accuracy of localization is worsened in Tunnel or Multipath propagation. Gyroscope is used in those conditions.
In dead reckoning, position data is estimated by integral of gyroscope, odometer and accelerometer. Depending on theaccuracy of gyroscope, errors of heading is accumulated. Therefore, high accuracy gyroscope is needed for dead reckoning.

Variation of position error of gyros with diﬀerent accuracy
Amount of 40
position error
(m)

h]

0°/

Distance
ΔL

40

00
30

00
20

10

00

0

]
00

[ 1°/hGyro bias 0.1°/h

00

10Position
Error

50

20

0

Error
Δdeg

[1

[ 20

°/h

]

30

Vehicle Speed : 50 km/h

Distance (m)04PART NUMBER

FOG & MEMS combined IMU

TAG350N 2
Calculation ※1

2：GNSS / INS / VScombined Navigation

Accelerometer

FOG ＆ MEMS combined IMUPERFORMANCE

00：Standard
Others : Exclusive※1 Please refer to page 15, 16 for the details of operation mode.

FOG & MEMS combined IMU

ItemSpeciﬁcation
Remark
85× 85 × 78.5 mm
Mass
600g Max
Power supply voltage 9 ～ 28V DC
Interface/ Baud rate RS232C：115.2 kbps（ﬁxed）
CAN：500kbps（Initial setting）
Output Cycle
RS232C：50Hz
CAN：50Hz
Gyro Range± 200deg/sec
Z axis：0.1 deg/h rms
Gyro Bias
X , Y axis：0.2 deg/s rms
SF : Scale Factor
Gyro Scale Factor Error Z axis：50ppm FS rms
FS : Full Scale
X , Y axis：0.2% FS rms

Item

FOG & MEMS combined IMU

Item

Vehicle Speed (VS) Input I/FPower Protection Circuit
GNSS Input I/F

CAN cable termination process

Remark

RS232C/CAN/Pulse✓✓－

Speciﬁcation

RemarkAcceleration Range ± 3G / ± 6G

Dimension

FUNCTION

Custom0：Accelerometer±3G
1：Accelerometer±6G

Acceleration Bias

5mG rms

Acceleration Scale
Factor Error

0.2%FS rms

Vibration

29.4m/sec² rms（5Hz ～ 2kHz）(3G rms)
20G 10ms

0.1deg rms
0.2deg rms
In-run Drift (Yaw)
0.0001deg/s rms
Operation temp. range -20～+60℃

Static Accuracy(Roll & Pitch)

Shock

Room temp.
Ambient temp.
Random vibration

USER CONFIGURABLE COMMANDS
Function

Alignment
Compensation

CAN Format, CAN ID
allocation

FOG & MEMS combined IMU

Explanation

If mounting surface is tilting, its attitude angle can berecognized as a zero (horizontal).

CAN format (standard/extended) and CAN ID allocation can
be changed.

There are a lot of other commands except for the above-mentioned. The customer canchange various settings.
Please refer to the speciﬁcation for the details.

■ Functional block diagram
TAG350

Roll
Pitch
Yaw

Gyro

Detect Angular Velocity
YZ

Accelerometer
Detect Acceleration

Thermal Sensor
Detect Temperature

Operation Sensor / CPU etc.

CPU

Sensor data
Acquisition/
Compensation
Inertial Calculation
Input/output

Generate Serial Signal

X

RS-232, 1PPS

DC/DC Converter
Generate Required Voltage

RS-232, CAN

External
GNSS Module※2

Upper System
INS data

Vehicle Speed

Angular velocity/ Acceleration/
Attitude Heading/GNSS position/
GNSS velocity

Power source 9～28V DC※2 External GNSS Module including cable and antenna is not attached to the product. If required, GNSS module should be prepared by customer.
■Connectable GNSS Module: KGM-810GRB1_PS_917/Position
Regarding the inquiries or purchases, please contact to our sales representative.

05

VehicleSpeed

OUTLINE DRAWING Dimension：mm

FOG & MEMS combined IMU■ TAG350

85±1

J1Connector
D02-M15PG-N-F0(JAE）

65±0.285±165±0.2X
TAG350N2
0.6

kg

DATE

Z

TYPE
MASS

（86）

78.5±1

3±0.2

YNO. ******
YYYY.MMTAMAGAWA SEIKI CO.,LTD.

（φ98）

MADE IN

JAPAN
615000102N40

4×φ3.6±0.2（φ85）■ Interface Cable EU8953N1001（sold separately）
1000±100
DE-C8N-J9-F1-1RN（JAE）
D02-M15SG-N-F0（JAE）

TJ-560-R（SATO PARTS）

155±10

TJ-560-B（SATO PARTS）
17JE-09H-1A(DDK)
DE-9SF-N(JAE)EU8953N1001

145±10

SMP-05V-NC(JST)06

MEMS IMU

AU7684
TAG300
TAG289We oﬀer 2 types of MEMS IMU (3 axis inertial sensor unit). The one is low cost, but GNSS interface model.
The other is GNSS/INS model with extended Kalman Filter.

MEMS IMUFEATURES

01
02
03

MEMS IMU

Attitude Angle <0.1°

Power Protection Circuit

Deﬁnition of Axis, CAN ID Allocation,
Oﬀset Cancel, Alignment, etc.

Output Cycle: 1kHz

Waterproof Case（TAG300 Series）

Extended Kalman Filter + Dead reckoning

Vehicle Speed (VS) Input I/F

User-conﬁgurable Setting

External GNSS Input I/F

IP65, M6 Mounting Conﬁguration,
0.5sq Wire Diameter■ Functional block diagram
AU7684 / TAG300 / TAG289
Roll
Pitch
Yaw

Gyro

Y

Z

Accelerometer
Detect Acceleration

Thermal Sensor
Detect Temperature
Magnetometer（Option）

Operation Sensor / CPU etc.

CPU

Sensor data
Acquisition/
Compensation
Inertial Calculation
Input/output

Generate Serial Signal

X

Detect Angular Velocity

RS-232, 1PPS

DC/DC Converter
Generate Required Voltage

RS-232, CAN

External
GNSS Module※1

Upper System
INS data

Vehicle Speed

Angular velocity/ Acceleration/
Attitude Heading/GNSS position/
GNSS velocity

Power source 8～28V DC※1 External GNSS Module including cable and antenna is not attached to the product. If required, GNSS module should be prepared by customer.
■Connectable GNSS Module: KGM-810GRB1_PS_917/Position
Regarding the inquiries or purchases, please contact to our sales representative.

07

VehicleSpeed

PART NUMBER

MEMS IMU■ AU7684（PCB Type）

AU7684N□□□□Calculation ※2

1: Leveling2: GNSS/INS/VS
combined Navigation

Accelerometer/Magnetometer

Custom0: Accelerometer±3G
1: Accelerometer±6G
2: Accelerometer±3G/Magnetometer(under development)
3: Accelerometer±6G/Magnetometer(under development)

00:Standard
Others: Exclusive■ TAG300（Waterproof Case Type）

TAG300N□□□□Calculation ※2

1: Leveling2: GNSS/INS/VS
combined Navigation

Accelerometer/Magnetometer

Custom0: Accelerometer±3G
1: Accelerometer±6G
2: Accelerometer±3G/Magnetometer(under development)
3: Accelerometer±6G/Magnetometer(under development)

00:Standard
Others: Exclusive■ TAG289（Case Type）

TAG289N□□□□Calculation ※2

1: Leveling2: GNSS/INS/VS
combined Navigation

Accelerometer/Magnetometer

PERFORMANCE

Item

Waterproof Case
Magnetometer

Vehicle Speed (VS) Input I/FPower Protection Circuit
GNSS Input I/F

CAN cable termination process

00:Standard
Others: Exclusive※2 Please refer to page 15, 16 for the details of operation mode.

MEMS IMU

Item
Speciﬁcation
P/N : AU7684 35 × 35 × 16.1 mm
Dimension P/N : TAG300 100 × 59.8 × 49.5 mm
P/N : TAG289 64 × 45× 33 mm
P/N : AU7684 30g Max
Mass
P/N : TAG300
250g Max
P/N : TAG289
Power supply voltage
8 ～ 28V DC
Interface/ Baud rate
RS232:115.2kbps
CAN：500kbps
RS232C：200Hz、CAN：1000Hz
Output Cycle
Gyro Range± 200deg/sec
Gyro Bias
0.2deg/sec rms± 0.2deg/sec

FUNCTION

Custom0: Accelerometer±3G
1: Accelerometer±6G

RemarkPCB Type
Waterproof Case Type（IP65)
Case TypePCB Type
Waterproof Case Type（IP65)
Case Type

User can change
CAN baud rate
Room temp.
Ambient temp.

MEMS IMU
Function✓✓

RS232 / CAN / Pulse

✓

✓

－

Remark

IP65：TAG300

Under development
Recommendation /Customization

Item

Gyro Scale Factor Error

Acceleration Range
Acceleration Bias
Acceleration
Scale Factor Error
Static Accuracy(Roll & Pitch)

Speciﬁcation
0.2%FS rms± 3G / ± 6G
0.0196m/sec2 rms（2mG）
0.049m/sec2 rms（5mG）
0.2%FS rms

0.1deg rms (Range 3G)
0.2deg rms (Range 3G)
In-run Drift ( Yaw)
0.01deg/s rms
Operation temp. range － 40～＋ 85℃
Vibration
29.4m/sec2 rms 5Hz ～ 2kHz
Shock
20G 10ms

RemarkFactory setting
Room temp.
Ambient temp.

Room temp.
Ambient temp.
Oﬀset-cancel applied

Random vibration

USER CONFIGURABLE COMMANDS
Function

Alignment Compensation
Deﬁnition of Axis
Update Cycle &Output Cycle

CAN Format,
CAN ID allocation

MEMS IMU

Explanation

If mounting surface is tilting, its attitude angle can berecognized as a zero (horizontal).
You can select not only Z axis but also X and Y axis asvertical axis.

The calculation update cycle & output cycle can be changed.
CAN format (standard/extended) and CAN ID allocation
can be changed.

There are a lot of other commands except for the above-mentioned.
The customer can change various settings.Please refer to the speciﬁcation for thedetails.

08

OUTLINE DRAWING Dimension：mm

MEMS IMU■ AU7684（PCB Type）
2.2
φ
4×

12以下

1.6

3.5以下

35±0.530±0.20.2±

35±0.530±0.2MEMS IMU■ TAG300（Waterproof Case Type）
100±3

5±5

49.5±2

1（14.9）
2×

φ

7±

0.5

59.8±2（30）80±0.5

UTS71412P（SOURIAU)■ TAG289（Case Type）※ Interface cable is attached to TAG289 series.

45±225±0.5900 +1000X
Z

Y

155±10

TJ-560-R（SATO PARTS）

TJ-560-B（SATO PARTS）

TAG289N****
No.****

DE-9SF-N(JAE)

57±0.550±264±2

17JE-09H-1A(DDK)

4×φ3.4
SMP-05V-NC(JST)33±2

145±1009

OUTLINE DRAWING Dimension：mm

MEMS IMU■ AU7684 Interface Cable EU8937N1000（sold separately）
1000±100

35±10

TJ-560-R（SATO PARTS）
155±10

TJ-560-B（SATO PARTS）
17JE-09H-1A Equivalent
DE-9SF-N Equivalent145±10■ AU7684 Interface Cable・Interface Cable with GNSS connector EU8937N1001（sold separately）
1000±10035±10155±10

TJ-560-R（SATO PARTS）
TJ-560-B（SATO PARTS）
17JE-09H-1A Equivalent
DE-9SF-N Equivalent

KVC-36 KURAMO

145±10

SMP-05V-NC（JST）■ TAG300 Interface Cable EU8940N1000（sold separately）
1000±10030±10155±15

TJ-560-R（SATO PARTS）
TJ-560-B（SATO PARTS）
17JE-09H-1A Equivalent
DE-9S-NR Equivalent145±15UTS6GN1412S（SOURIAU）■ TAG300 Interface Cable・Interface Cable with GNSS connector EU8940N1001（sold separately）
1000±10030±10155±15

TJ-560-R（SATO PARTS）
TJ-560-B（SATO PARTS）
17JE-09H-1A Equivalent
DE-9SF-N Equivalent

UTS6GN1412S（SOURIAU）
145±10

SMP-05V-NC（JST）

10

MEMS Gyro Sensor

TAG206N5000
TAG204N5000

When an oscillating object is rotated, Coriolis Force works in the direction perpendicular to the vibration,and the other vibration occurs.

This induced vibration is detected and converted into voltage proportional to the amplitude of the vibration.

Widespread MEMS Gyro
TAG206N5000

DETECTION

MEMS Gyro Sensor

Rotation Axis

MEMS Gyro Sensor

5.4±0.3.3±0
2.6

AngularRate：Ω

Vd

5.9

5±
0.3

When excited（mm）

Supply Voltage

MIN

Coriolis Force：F 0 =2mvΩ 0
Mass：mVelocity：v

Unit
V

MIN

mA

± 60deg/sec

deg/sec

Maximum Output

16383d-3.9

1000HzHz

0d

Minimum Output-

Analog Output

TYP

5V ± 5%MAX

9mA Max.

Measurement Range
Sampling Rate

Inclined to the directionof Pin 1

VmA± 60deg/sec

deg/sec

-

-

0.3

V
V

-12

+12

deg/sec-12+12

deg/sec

Zero Rate Output
with temperature
variance-3+3

deg/sec-3+3

deg/sec90

LSB/deg/sec

16.2

+2

％

-2

Linearity

Scale Factor
Variation with
Temperature

Temperature Output

Scale Factor of
Temperature Sensor

74

-0.5

82

-2
8102d
-16

8192d
-18

+0.5

8282d
-20

%FS

LSB/℃

-0.5

2.08
-3.8

18

19.8

+0.5
+2

2.1
-4

RemarkUnit

Zero Rate Output

Scale Factor

11

5V ± 5%MAX

9mA Max.

Consumption Current

θ ＝0゜
～20゜

MEMS Gyro Sensor

Digital Output

TYP

Tilt angle

When detected

ELECTRICAL SPECIFICATION
Items

0

θ

2.12
-4.2

Ta=-40 ～ +85℃
Digital Output：8192d is a standard
Analog Output：2.1V is a standard
Ta=-40 ～ +85℃

mV/deg/sec Ta=-40 ～ +85℃
%FS
％
V

mV/℃

25℃

Ta=-40 ～ +85℃

5

4.3
8.7

High Accuracy MEMS Gyro
TAG204N5000

9

（mm）

ELECTRICAL SPECIFICATION
Items
Supply Voltage

MIN

Measurement Range

5V ± 5%MAX

Maximum Output
Minimum Output

Zero Rate Output-6

Scale Factor

74

Zero Rate Output
with temperature variance-2

Linearity-0.5

Temperature Output

8102d

-2

-16

V

mA

deg/sec

16383d

-

0d

82

8192d
-18

RemarkUnit± 60deg/sec
1000HzSampling Rate

Scale Factor of
Temperature Sensor

TYP

Digital Output

9mA Max.

Consumption Current

Scale Factor
Variation with Temperature

MEMS Gyro Sensor

Hz
-

+6

deg/sec90

LSB/deg/sec

+2

％

+2

+0.5
8282d
-20

deg/sec%FS

LSB/℃

Ta=-40 ～ +85℃
Digital Output：8192d is a standard
Ta=-40 ～ +85℃
Ta=-40 ～ +85℃

25℃

Ta=-40 ～ +85℃

IMU Simulator software
In dedicated software is able to graph monitor and data outputs of the IMU's output.

*There are two types of software with GNSS or without GNSS. Please check at the time of your order.
Software can be downloaded free from our HP.

〈MEMS IMU HP〉https://mems.tamagawa-seiki.com/download/■ Simulator software

2D monitor

Graph monitor

Graph monitor → Data output
12

Interferometric Fiber Optic Gyroi-FOG

TA7774High accuracy [0.1°/h] Gyro (1-axis), which is a key technology to realize fully autonomous driving.

FEATURES

01
02
03

i-FOG

High-accuracy■ i-FOG

Promotional Video

Achieved [0.1°/h] which is required for fully autonomous driving.

Low-price

See thedemonstration of
i-FOG localization.

Our unique technology for winding and Fiber Optical IC realizes
cost reduction.

https://www.tamagawa-seiki.co.jp/
products/gyro/1-axis-gyro-TA7774.html

Closed-loop Typei-FOG

CENTIMETER CLASS LOCALIZATION

Route Map

Localization by i-FOG
Latitude

The accuracy of localization of vehicles is increased to centimeterclass by using i-FOG.
It is necessary to maintain the accuracy of localization at
centimeter class under GNSS-denied environment.
GNSS

Longitude

Red line is the track of localization by i-FOG

IMU

Vehicle Speed (VS)POSITION ACCURACY BY GYRO ERROR & VEHICLE SPEED

i-FOG

The accuracy of i-FOG (TA7774) is 0.1°/h, which is able to keep high accuracy localization for a certain period of time.
Position Accuracy at 10km/h

Position error (m)

8
6
5
3

General type
FOG

2
1
0

13

X（0.1°/ｈ）
X（1°/ｈ）
X（10°/ｈ）
X（20°/ｈ）

7

4

0

200

10

Gyro Accuracy

General typeMEMS Gyro

9

400
600
Distance (m)800

TA77741000

Gyro Accuracy

9

X（0.1°/ｈ）
X（1°/ｈ）
X（10°/ｈ）
X（20°/ｈ）

8

Position error (m)10Position Accuracy at 100km/h

7
6
5
4
3
2
1
0

0

200

400
600
Distance (m)

800

1000

TA7774

Part Number

0.1°/h（1δ）（25℃ static）

Bias Repeatability

0.1°/h Max.

Bias Instability
Random Walk

0.01°/√h Max.

Scale Factor Linearity± 100ppm

FS

400g Max.

Mass±5V, ±15V

Power-supply voltage±15V：0.2A Max.

RS232：115.2kbps（ﬁxed）

Interface/ Baud rate

－20～＋60℃

Operating Temperature

ALLAN VARIANCEFEEDBACK SIGNAL
GENERATING CIRCUITSCALE FACTOR & LINEARITY

i-FOG

Random walk：0.01°/√h

i-FOG
0.01

250
200

FOG OUTPUT（°/s）

150

0.005

100

50

0.1

0

-50

-100

0.01

0.01

DETECTORCIRCUITOUTPUT1

0.001

Phase diﬀerence to be
detected becomes 0.

－30～＋70℃

Non-operating Temperature

10

LIGHT SOURCECIRCUIT50Hz

Output Cycle

FIBER OPTIC
COIL

OSCILLATIONCIRCUIT±5V：1.5A Max.

Power Consumption

OPTICALIC

OPTICAL DETECTOR
MODULE±100ppm

Scale Factor Accuracy

i-FOG

COUPLERLIGHT SOURCEMODULE±200°/sec

Dynamic Range

ALLAN DEVIATION［°/h］

CONFIGURATION

i-FOG

-300

-200

-100

0

100

200

300

-200
1

10

100

1000

10000

INTEGRATION PERIOD［s］-250

100000i-FOG

150 ±50

85 ±1

45 ±1

65 ±0.2

i-FOG

65 ±0.285 ±1TA7774SERIAL NO.

4×φ3 . 6 ±0.2

（φ9 8 ）

EU8954N1000（sold separately）
1000±100（φ8 5 ）

155±10

TJ-560-R（SATO PARTS）

TJ-560-B（SATO PARTS）+5V GND -5V

17JE-15H-1A2-CF (DDK)
DA-15SF-T-N (JAE)

3±0.2

＋

D-Sub15pin(JAE：DA-15PF－N Equivalent)■ Interface Cable-0.01

INPUT RATE（°/s）*For more details, contact to our technical support written in thelast page.

OUTLINE DRAWING Dimension：mm■ TA7774

0-0.005-150

0.1

LINEARITY（％FS)

SPECIFICATION

TJ-560-BL（SATO PARTS）
17JE-09H-1A (DDK)
DE-9SF-N (JAE)EU8954
N1000+15V GND -15V
155±10

TJ-560-R（SATO PARTS）

TJ-560-B（SATO PARTS）

TJ-560-BL（SATO PARTS）

14

Technology
About Operation Mode
1, Leveling Mode
The feature of Leveling mode is stable output of attitude angle (roll & pitch) by a combination of accelerometers andgyroscopes.

If the device is aﬀected by acceleration or centrifugal force for long hours, the errors of attitude angle may be
increased. However, it can be suppressed by a compensation of GNSS and vehicle speed signal input.

Overview, Conﬁguration

CPU

Interface

OutputCalculation

SerialSignalGeneration

RS232、CAN

Sensor

MEMS Gyroscope
Accelerometer

Angularvelocity

Acceleration

GNSS
signalAttitudeHeading

VehicleSpeed

Correction of Attitude

2, GNSS/INS/VS Mode
GNSS/INS/VS is performed by combining gyroscopes angular velocity and accelerometers (INS data), external GNSS

Technology

data and vehicle speed. In addition to GNSS and vehicle speed data, algorithm (Kalman ﬁlter) is used to estimate theerror of INS data , and improve accuracy. It is also possible to output the position data even in GNSS-denied
environment.

Overview, Conﬁguration

Sensor

MEMS Gyroscope
Accelerometer

Angularvelocity

Acceleration

CPU

InterfaceCalculation

SerialSignalGeneration

Kalman Filter

Bias estimation forgyroscopes &accelerometers
15

Bias estimation
for position,
speed, attitude andheadingHeading

Output

RS232、CAN

Position
Velocity

Velocity

Position

AttitudeHeading

GNSS
signalVehicleSpeed

Case Study for GNSS/INS Navigation

Dead Reckoning, a method of calculating position with GNSS/INS combined navigation in GNSS-denied
environment such as a tunnel. Please take a look at the demonstration from here.

https://mems.tamagawa-seiki.com/product/multisensor.html

3, Leveling VS GNSS/INS/VS
Operation Mode
GNSS

Inertial Sensor
・Angular velocity
・Acceleration

Attitude・Heading・Roll・Pitch・Yaw

OutputFormatGNSS・Latitude ・Longitude
・Altitude ・Velocity
・Time・Satellite

Dead-reckoning
・Latitude
・Longitude
・Altitude

Estimated Sensor Bias・Angular velocity
・Acceleration

Application

Leveling

GNSS/INS/VS

Disconnected

Connected

Connected *necessary

✓

✓

✓

✓

✓

✓

－

✓

✓

－

－

✓

－

－

✓

●Measurement of Attitude,
Heading●Motion Sensing●Vibration●Monitoring System●Roll-over prevention Control●Power Assist●Localization in GNSS-denied
environment(Autonomous-driving,Self-driving)●High-accuracy measurementof Attitude & Heading

16

KEY WORDS
Term

Type

Inertial Measurement
Unit（IMU）

MEMS Gyro
Fiber Optic Gyro
（FOG）
Ring Laser Gyro
（RLG）

Performance / Term

Angular Velocity
Acceleration

Explanation

Inertial measurement unit (IMU) is used not only for measuring dynamics, posture, andorientation of various movements, but also for measuring position. Tamagawa Seiki
manufactures various kinds of products such as MEMS Gyro, Fiber Optic Gyros (FOG) andInertial Measurement Unit (IMU). Therefore customers can select the sensor for a wide range
of applications.
Sensor making use of MEMS technology which detects the acceleration by using inertial force(Coriolis force) coming from vibration or rotation.
Turn the optical ﬁbers like a coil in CW and CCW and input light to both directions. By theinterference of the output, the wavelength is changed due to Doppler eﬀect according to the
motion (red and blue shift). A gyroscope which detects and outputs the change amount.

Ring Laser Gyroscope (RLG) consists of a ring laser having two independent counterpropagating resonant modes over the same path. The diﬀerence in the frequencies is used todetect rotation. It operates on the principle of the Sagnac eﬀect which is also usd for Fiber
Optic Gyro (FOG).
Change ratio of angle (rotation speed, rotation angle) per unit time.

Change ratio of speed per unit time. The gravity is a kind of the acceleration.

Attitude angle

The angle between the plane of object and the horizontal ground. Inclination towards
front-back is called "pitch" while towards right-left is called "roll".

Heading angle

Heading angle is compass direction in which the object's nose is pointed. Without compass
direction, it is called "yaw" angle.

Dynamic Range

Measurable range of a sensor from minimum to maximum of a motion. The reciprocal of a
dynamic range is a scale factor.

Bias

Deviation from ideal center. Diﬀerence between output in a stationary state and ideal zero. It
is also called zero point bias or oﬀset. It becomes an element of the error (integration error)
in case of angle calculation.

Technology

Drift
Random Walk

Drift is the indication of bias variation size under the inﬂuence of environmental condition
such as temperature (rise or fall), power supply variation or vibration. There is also a
successive change shifting slowly.

Digitalized value of degree of variation (white noise). It is considered to be the noise which asensor has.

Scale Factor

Ratio of sensor output changed by input. It is also called sensitivity (Sensitivity is
distinguished from scale in the IEC standard).

Linerity

Linearity is the property of a mathematical relationship (function) that can be represented asa/A×100 (％) .

Resolution

The resolution is the minimum input of angular velocity that the gyro can identify. To
measure the resolution, input the minute angular velocity to the gyro on the precision rate
turntable and see the signiﬁcant change in the gyro output. In some cases, quantization error
is interpreted as resolution.

Cross Coupling

17

Please check for details.

Sensitivity against the detection axis by another axis input. Misalignment which indicatesdirection accuracy is a kind of the cross coupling.

Term

Performance / Term

Allan Variance

Bias instability

Explanation

Plot of quotient when the integrated value of gyro output is divided by integral time. It showsa cluster time (averaging time) in a horizontal axis and an Allan deviation (σ) in a vertical axis.
We can read the random walk, bias stability etc. from the plot and also represent the noise
component of gyro in a graph.
Bias instability is one of indicators of gyroscope which is measured by Alan variance method.
The smaller the number, the higher the performance of the gyroscope.

Communication

Calibration

Calibration is the comparison of measurement values acquired from a device with those of acalibration standard equipment.

Warm Up

Warming up operation after turning on the power.

RS232

RS-232 is a serial port interface standard standardized by the Electronic Industries Alliance(EIA). It is widely used as a communication standard for personal computers andcommunication devices.

CAN

Calculation

GNSS/INS Hybrid
Navigation System
Leveling Calculation
Inertia calculation
Inertial Navigation

CAN is a communication standard standardized by ISO-11898. Originally used as acommunication standard inside automobiles, it is now widely used in the ﬁelds ofconstruction machinery, agricultural machinery and factory equipment.

Compound navigation of GNSS and INS (Inertial Navigation System). Technology for highaccuracy and stable navigation. The error estimation of inertial sensor by Kalman ﬁlter
improves the accuracy.
Inertial operating algorithm of MEMS-IMU (IMU consists of MEMS gyros and MEMS
accelerometers) made by Tamagawa. It enables a high precision dynamic posturemeasurement to a low cost (low accuracy) gyro. ※Leveling Calculation vs GNSS/INS/VS

Calculations are performed only with the built-in gyro and accelerometer without referring to
GNSS or external speed. This method can be used only in FOG IMU and RLG in which
high-precision gyros are used.
A method of calculating the position and direction using only inertial sensor. However, there
is a characteristic that the error accumulates and increases when moving a long distance.

Function

Kalman Filter

This is a calculation method that improves the accuracy of data by estimating the error for aquantity (position, velocity) that changes over time.

Oﬀset Cancel

This function calculates the average value of bias (zero point error) at a certain time. The
average value of the bias is oﬀset in the subsequent operations.

Alignment

If there is a mounting error or tilt on the IMU installation surface, the tilt is normally output
based on the horizontal plane, but when using this function, the installation surface can be
set to zero.

Dead zone(Yaw)
Dead Reckoning
Sensor Fusion

In order to suppress the yaw angle drift, the Z-axis of angular velocity in the dead zone isconverted to zero and is not reﬂected in the yaw angle calculation.

Technology of position measurement with high accuracy even in a tunnel without GPS signalby the compound arithmetic procession of the information from gyro sensor, accelerometeretc.
By compounding data from several sensors, improve the measurement reliability of the unit
or complement defects of each sensor.

18

WARRANTY

When ordering, please contact our Sales Department as the contents of thiscatalog are subject to change without notice.
The outline of operation and the examples of an application circuit indicatedin this catalog are only showing standard operation and usage of electronic
components and do not guarantee the operation by actually used equipment.
Therefore, please design equipment at your own risk in case you use our
products. We cannot take responsibility for damages resulting from the use of
our products.
The technical information containing the outline of operation and circuit
diagram indicated in this catalog does not mean consent of intellectual property
rights, such as patent right of our company or a third party, and copy right.
Moreover, it does not guarantee that enforcement of a third party’s intellectual
property rights or other rights can be performed. Therefore, we do not takeresponsibility for the infringement of a third party’s intellectual property rights
or other rights resulting from the use of our technical information.
Products shown in this catalog are designed and manufactured with an object
for general use, such as the ordinary industrial use, general oﬃce work, andpersonal/home use. They are not designed and manufactured for the use
which requires high reliability（under-water stations and space satellites）,
and the use which requires high safety and if the safety is not secured, it hasserious influence socially and directly onto life and body（nuclear reaction
control in nuclear facilities, airplane automatic ﬂight control, air traﬃc control,
traﬃc control in a mass transportation system, medical equipment for life
maintenance, and missile launch control in an arms system）. Therefore those
who are considering use of our products in these ﬁelds are advised to consult
our Sales Department in advance. We cannot take responsibility for damages
resulting from the failure in the consultation.
Failure of electronic components occurs in a certain probability. So we request
you to establish safety designs, such as a redundant design of equipment, adesign to prevent spread of a ﬁre, an over-current prevention design, and amalfunction prevention design, even if the electronic components should break
down so that an accident resulting in injury or death, a ﬁre accident, and social
damage may not take place.
In case our product in this catalog corresponds to a cargo or technology
regulated based on “a foreign exchange and a foreign trade law” , thepermission based on the law is required in exporting the product.

A COMPANY OF TAMAGAWA SEIKI CO., LTD.
■ International Marketing Sales Department
Head quarters:
1-3-1 Haba-cho, Iida, Nagano Pref. 395-0063 Japan
PHONE : +81-265-56-5423
FAX : +81-265-56-5427
Ideas make technology fun

https://mems.tamagawa-seiki.com/en/'21.01

T12-1721N3
This catalogue is current as of Jan. 2021.
ALL speciﬁcations are subject to change without notice